First of all, this is a weakness of XFCE 4.12 that will be addressed (we are told) with the release of Xfce 4.14 in August. Second, you may want to use a script, such as the one described in this Wiki article: https://mxlinux.org/wiki/xfce/xfce-commands-and-other-useful-stuff/#dualmonitor Third, thi...